The criminality rate in Colombia (crime/population) grew rapidly between the middle seventies and eighties, since then it had shown a declination, but the country still observes high indices of criminality, mostly in homicides and kidnapping. In a similar way defense, security and justice spending have grown. This paper will present some reasons that explain, from an economic point of view, the growth of these spending, the conditions that make it increase or decrease in an optimal way and which establish a complementary relation (marginal) between the magnitude and the efficiency of these spending.